All the main areas theres likely to be wear & tear & stone chipping (rear stays [heel rub], top & bottom tubes, etc) plus the cable rub spots ... though I missed one and now I'm sad I have a silver bit on my black frame

Just applied invisiframe on my hpc 160 and you can barely tell its applied. Got the matt kit to go with the matt finish and even though it's expensive, it's only a small investment in the grand scale of things to protect the finish